Ornamental sweetpotato plant named &#39;NCORNSP-023BWAM&#39;

ABSTRACT

‘NCORNSP-023BWAM’ is a compact, non-twining, upright variety producing many short shoots. It is distinguishable from other cultivars by its purple toothed-slightly lobed leaves with a cordate base; a compact habit and erect mounding plant architecture. The purple-toothed leaves of this plant, short internodes, and the plant architecture are what make ‘NCORNSP-023BWAM’ unique amongst the current ornamental sweetpotatoes in the marketplace. ‘NCORNSP-023BWAM’ also exhibits very good vigor and is well branched. In greenhouse and field trials conducted since 2012, ‘NCORNSP-023BWAM’ has been shown to be much less vigorous than  Ipomoea batatas  ‘Margarita’ and ‘Blackie’ and is suitable for use as a landscape or containerized plant. The production of flowers by ‘NCORNSP-023BWAM’ is sporadic under short day conditions.

Latin name of the genus and species: The Latin name of the novel, ornamental plant variety disclosed herein is Ipomoea batatas (L.) Lam.

Variety denomination: The inventive cultivar of Ipomoea batatas disclosed herein has been given the varietal denomination ‘NCORNSP-023BWAM’.

BACKGROUND OF THE INVENTION

Ipomoea batatas is a member of the morning glory family Convolvulaceae. This species is grown worldwide and it exhibits a wide range of plant forms and colors. The cultivated members of Ipomoea batatas grown by farmers worldwide are commonly produced for consumption of their nutritious, enlarged storage roots. These types typically produce a fast growing green vine that has a wide variety of leaf shapes ranging from palmate and deeply lobed, to cordate or triangular shaped leaves with no lobes.

Like their edible forms, Ipomoea batatas ornamental sweetpotato (OSP) plants are a heat-loving, drought-tolerant, perennial vine typically grown as an annual. However, ornamental sweetpotato plants are distinguished from the edible cultivated forms in that they possess unique foliage colors, leaf shapes, and growth habits, which have significant value in the ornamental marketplace.

Ornamental sweetpotatoes are desirable in the landscape and ornamental industries because their foliage comes in a wide variety of colors (e.g. pale yellow to dark purple with some exhibiting temporal and individual leaf color variegation patterns) and plant shapes (e.g. mounded and very compact to prostrate and highly spreading). They can be grown in a potted plant and/or mixed planting format, and they have the ability to cover a large space or hang over walls and decorative pots creating brightly colored and textured backdrops in gardens and patios. Most ornamental sweetpotatoes continue to grow throughout the entire growing season and require little maintenance. Moreover, these plants have few insect or disease problems.

To meet the growing horticultural demand for ornamental sweetpotatoes, it is desirable to produce new cultivars of ornamental sweetpotato with new or improved foliage colors, variegation patterns, leaf shapes, and plant architectures. In addition, it would be advantageous to develop cultivars of ornamental sweetpotato exhibiting a more compact growth that do not out-compete other species in mixed containers.

‘NCORNSP-023BWAM’ was bred to meet the increasing demand for new ornamental sweetpotatoes. ‘NCORNSP-023BWAM’ is a compact, non-twining, upright variety producing many short shoots. It is distinguishable from other cultivars by its purple toothed-slightly lobed leaves with a cordate base; a compact habit and erect mounding plant architecture. The purple-toothed leaves of this plant, short internodes, and the plant architecture are what make ‘NCORNSP-023BWAM’ unique amongst the current ornamental sweetpotatoes in the marketplace. ‘NCORNSP-023BWAM’ also exhibits very good vigor and is well branched. In greenhouse and field trials conducted since 2012, ‘NCORNSP-023BWAM’ has been shown to be much less vigorous than Ipomoea batatas ‘Margarita’ and ‘Blackie’ and is suitable for use as a landscape or containerized plant. The production of flowers by ‘NCORNSP-023BWAM’ is sporadic under short day conditions.

Lineage. ‘NCORNSP-023BWAM’ (breeding designation NC8105-002ORN) originated from a self-compatible cross between the proprietary Ipomoea batatas breeding lines NC7218-004ORN (the female parent; not patented) and NC7218-004ORN (the male parent; not patented). Botanical seed was harvested from this and other ornamental sweetpotato clones planted in our winter greenhouse-crossing block between September of 2012 and March of 2013 in Raleigh, N.C. NC7218-004ORN resulted from open pollinated seed harvested from the proprietary Ipomoea batatas breeding line NC6688-001 (the female parent; not patented) planted in our summer ornamental trials between June of 2008 and November of 2008. Botanical seed from this family was planted in the greenhouse in February 2012. The first cycle of selection on the population was exercised in the seedling trays and survivors were transferred to a single 6-inch pot, which was then maintained in the greenhouse. Cuttings (2 each) were taken from the plants in April and planted in the field as 2-plant unreplicated plots during early June 2012. The single, individual plant now known as ‘NCORNSP-023BWAM’ was selected Jul. 30, 2012 based on its combination of exceptional features, and has been propagated asexually since that time.

Asexual Reproduction. Since its selection, Ipomoea batatas ‘NCORNSP-023BWAM’ has been asexually reproduced in North Carolina predominantly by vegetative propagation of vine cuttings. Successively, there have been five cycles of vegetative propagation, one cycle of tissue culture micropropagation, and multiple vegetative propagation cycles to increase the plant population. Asexual reproduction of ‘NCORNSP-023BWAM’ by cuttings has shown that the unique features of the new cultivar are stable and the plant reproduces true to type in successive generations.

SUMMARY OF THE INVENTION

‘NCORNSP-023BWAM’ is a compact, non-twining, upright variety producing many short shoots. It is distinguishable from other cultivars by its purple toothed-slightly lobed leaves with a cordate base; a compact habit and erect mounding plant architecture. The purple-toothed leaves of this plant, short internodes, and the plant architecture are what make ‘NCORNSP-023BWAM’ unique amongst the current ornamental sweetpotatoes in the marketplace. ‘NCORNSP-023BWAM’ also exhibits very good vigor and is well branched. In greenhouse and field trials conducted since 2012, ‘NCORNSP-023BWAM’ has been shown to be much less vigorous than Ipomoea batatas ‘Margarita’ and ‘Blackie’ and is suitable for use as a landscape or containerized plant. The production of flowers by ‘NCORNSP-023BWAM’ is sporadic under short day conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The photographs in the drawings were made using conventional techniques and show the colors as true as reasonably possible by conventional photography. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new Ipomoea batatas.

FIG. 1 is a color photograph of a typical specimen of greenhouse grown Ipomoea batatas ‘NCORNSP-023BWAM’ in a 6-inch pot from the top, 49 days after planting.

FIG. 2 is a color photograph of a typical specimen of Ipomoea batatas ‘NCORNSP-023BWAM’ in a 6-inch pot from the side, 49 days after planting.

FIG. 3 is a color photograph showing the variety of leaves produced by Ipomoea batatas ‘NCORNSP-023BWAM’ and the lower surface of the leaf (bottom row), 49 days after planting.

FIG. 4 is a color photograph showing the variety of roots produced by Ipomoea batatas ‘NCORNSP-023BWAM’ in the field, 115 days after planting.

DETAILED BOTANICAL DESCRIPTION OF THE NEW VARIETY

The following is a detailed description of the botanical characteristics of a new and distinct cultivar of Ipomoea batatas plant known by the cultivar name ‘NCORNSP-023BWAM’. All colors cited herein refer to The Royal Horticulture Society Colour Chart designations (The Royal Horticultural Society, London, 1995, 4^(th) ed.) except where general terms of ordinary dictionary significance are used. Plant descriptions are based on the standardized international sweetpotato descriptors established jointly by the International Potato Center (CIP), Lima, Peru; The Asian Vegetable Research and Development Center (AVRDC), Taipei, Taiwan; and the International Board for Plant Genetics Resources (IBPGR), Rome, Italy (CIP, AVRDC, IBPGR. 1991. Descriptors for Sweet Potato. Huaman, Z., editor. International Board for Plant Genetic Resources, Rome, Italy, 134 pp.). Where dimensions, sizes, colors, and other characteristics are given, it is to be understood that such characteristics are approximations or averages set forth as accurately as practicable.

The descriptions reported herein are from a group of 49-day-old specimens grown individually in six-inch azalea pots. The plants were grown in Raleigh, N.C., under commercial practice in a glass-covered greenhouse, where, during the fall, day and night temperatures range between 30-40° C. and 22-26° C., respectively. After rooting, plants were treated with 200 ppm 20-10-20 fertilizer daily. Plant histories were taken in November 2015 at the Horticultural Field Laboratories in Raleigh, N.C. Ipomoea batatas ‘NCORNSP-023BWAM’ has not been observed under all possible environmental conditions; therefore, the phenotype may vary under different environmental conditions such as season, temperature, light intensity, day length, cultural conditions, and the like, without however, any variance in the genotype.

-   Classification:     -   -   Botanical name.—Ipomoea batatas (L.) Lam.         -   Common name.—Ornamental Sweetpotato.         -   Variety name.—‘NCORNSP-023BWAM’. -   Growth conditions: Ipomoea batatas ‘NCORNSP-023BWAM’ has very good     vigor and a moderate growth rate. In locales with mild winter     conditions, Ipomoea batatas ‘NCORNSP-023BWAM’ will grow perennially;     otherwise it is an annual plant. Similar to other cultivated     sweetpotatoes, wind or rain rarely causes much damage to     ‘NCORNSP-020BWL, but if damage does occur, the plant drops the     damaged leaves and grows new shoots at nodes where the leaves were     lost. -   Aboveground structure and coloration: FIGS. 1, 2, 3, and 4 show the     shape and coloration of a typical specimen of Ipomoea batatas     ‘NCORNSP-023BWAM’. Color may vary somewhat in response to     temperature and nutrient stress. Overall, this cultivar is a     compact, non-twining, upright herbaceous plant that has an average     height of ˜22.8 cm and an average area spread of ˜54.0 cm. The     growth habit of this plant is to grow upright with shoots growing     upward and outward. -   Branches:     -   -   Branching habitat.—Freely-branching with ˜3-4 primary             lateral branches coming off the stem. Dense foliage and no             pinching is required to stimulate branching. Branch texture             is smooth with slight pubescence.         -   Vegetative lateral branching.—Length ˜29.6 cm. Diameter:             ˜0.6 cm. Internodes are very short with an average length of             ˜0.6 cm.         -   Secondary lateral shoots.—Many lateral branches are formed             and each axil has latent shoots. Length: ˜12.5 cm. Diameter:             ˜0.2 cm. Internodes are short with an average length of ˜1.7             cm.         -   Stem.—Round and smooth with an upward, outward, and slightly             undulating aspect and strong, slightly flexible, non-brittle             strength. Color: Purple (RHS N77A) with green (RHS144A) at             apical meristem.         -   Adventitious roots.—Present at nodes. Color: Purple (RHS             N77A) with yellow green (RHS 145C).         -   Petiole.—Petioles are held upward and display the leaf             slightly vertical with a slight undulation. Leaf petiole has             a smooth texture with a matte finish and slight pubescence.             Length: ˜12.4 cm. Diameter: ˜0.3 cm. Color: Purple (RHS             N79B). -   Foliage. Leaves are alternate and tend to slightly spiral around the     stem. They are toothed-slightly lobed with a deltoid base. Leaves     have 5-6 shallow lobes per leaf. Leaf shape is somewhat variable as     is size (see FIG. 3).     -   -   Quantity.—Moderately-heavily foliated, with ˜27 leaves per             lateral branch.         -   Mature leaf length.—˜17.7 cm.         -   Mature leaf width.—˜15.0 cm.         -   Central lobe length.—˜8.0 cm.         -   Central lobe width.—˜7.6 cm.         -   Secondary lobe length.—˜1.4 cm.         -   Secondary lobe width.—˜1.3 cm.         -   Mid-vein lobe length.—˜3.1 cm.         -   Mid-vein lobe width.—˜2.0 cm.         -   Tertiary lobe length (when present).—˜2.6 cm.         -   Tertiary lobe width (when present).—˜1.5 cm.         -   Leaf margin.—Toothed.         -   Leaf apex.—Deltoid-acute.         -   Leaf base.—Deltoid.         -   Lobe apex.—Lanceolate-deltoid.         -   Lobe base.—Deltoid.         -   Leaf texture.—Smooth texture and matte finish.         -   Venation.—Pinnate to cross-venulate. Texture: Smooth.         -   Color.—Leaves are yellow green when immature, maturing to             purple and range within those palates as they mature. See             also Table 1.

TABLE 1 Leaf color of Ipomoea batatas Leaf Structure Upper Surface Lower Surface Young Leaf Yellow Green Yellow Green (RHS 144) (RHS144A-B) Mature Leaf Greyed Purple (RHS Purple (RHS N77C) to N186A, N186A-186B) Greyed Purple (RHS N186C) Vein-mature leaf Purple (RHS N77A) Purple (RHS N79B) Vein-young leaf Yellow Green Yellow Green (RHS 144B) (RHS 144A-B)

-   Inflorescence: Flowers sporadically throughout the season in     response to a variety of stressful conditions (e.g., drought,     nutrient stress, cloudy weather). Shorter day lengths enhance     flowering, but the precise photoperiod for flower induction is     currently unknown. Solitary, regular funnel-form flowers arising     from leaf axils on secondary lateral branches are formed. Peduncles     are purple (RHS N77A) and have a smooth texture. Peduncle length:     ˜3.9 cm, peduncle width: ˜0.2 cm. Flower buds are pale purple (RHS     76C-76D) and elliptic. Flower bud length: ˜4.6 cm, flower bud width:     ˜0.5 cm. Corolla width: ˜4 cm, corolla length: ˜3 cm. Limb color:     Light purple (RHS 76B-76C) on both the inner and outer surface. The     inner throat color gets lighter from base to limb going from purple     (RHS 77A) at the base to light purple (RHS 76B-76C) near the limb.     The limb is rounded with no fragrance. The flower averages five     sepals. The two outer sepals are shorter than the inner sepals.     Average sepal length: ˜0.8 cm, average sepal width: ˜0.3 cm. The     sepals are ovate to elliptic with a caudate apex and are purple (RHS     N77A-N77C) in color. Sepal texture is glabrous on both the upper and     lower surface. A single pistil consists of one style and one stigma     ˜2 cm in length. Stigma and style are both cream (RHS 157A). The     stigma is exerted relative to the stamens. The ovary is yellow (RHS     1C) and superior with two locules that contain one or two ovules. At     the base of the ovary are orange basal glands (RHS 163A) containing     nectar, which cover halfway up the ovary. The flower averages five     stamens. Each stamen consists of a single purple fading to cream     filament averaging ˜1.2 cm in length topped with a single     cream-white anther averaging ˜0.3 cm in length. Filament color:     purple (RHS 75A) fading to cream (RHS N155A). Anther color: cream     (RHS 155A). Pollen color: cream (RHS 155A). Pollen amount is     moderate. Fruit has not been observed under normal greenhouse     conditions. -   Storage root coloration: Plants form no, to small, underground     storage roots that are occasionally malformed and do not meet USDA     Sweetpotato Storage Root Grade Standards (see FIG. 4). Fibrous roots     are typically cream (RHS 155B). Storage roots that are formed     possess greyed yellow (RHS 161C-161D) skin with hints of greyed red     (RHS 182C-182D) and a yellow white flesh (RHS 158C-158B). -   Disease or pest resistance: ‘NCORNSP-023BWAM’ is susceptible to     whiteflies and spidermites in a greenhouse environment.     ‘NCORNSP-023BWAM’ is susceptible to damage by Japanese beetles under     outdoor conditions. The susceptibility of ‘NCORNSP-023BWAM’ to other     known insects and pathogens of sweetpotato is unknown. Under low     light conditions, slight edema may occur. -   Comparison with other Ipomoea batatas cultivars: ‘NCORNSP-023BWAM’     is very distinct based on leaf shape and plant architecture. Of the     common cultivars of ornamental sweetpotato, ‘NCORNSP-023BWAM’ is     best compared with the ‘Sweet Caroline Sweetheart Purple’ (U.S.     Plant Pat. No. 18,573) and ‘Sweet Caroline Bewitched Imp’ (U.S.     Plant Pat. No. 23,651) cultivars (Table 2). Like ‘Sweet Caroline     Sweetheart Purple’ and ‘Sweet Caroline Bewitched Imp’,     ‘NCORNSP-023BWAM’ has purple leaves. However, the leaves of     ‘NCORNSP-023BWAM’ are toothed-slightly lobed with a deltoid base     compared to those of ‘Sweet Caroline Sweetheart Purple, which are     entire with a deltoid base and those of ‘Sweet Caroline Bewitched     Imp’, which are slightly lobed and toothed with a reniform-cordate     base. ‘NCORNSP-023BWAM’ has a moderately compact to compact,     upright, non-twining plant habit compared with the moderately     compact to compact, upright plant habit of ‘Sweet Caroline     Sweetheart Purple’ and the compact, upright, non-twining habit of     ‘Sweet Caroline Bewitched Imp’. Furthermore, ‘NCORNSP-023BWAM’ has a     larger average leaf size compared with the smaller leaves of ‘Sweet     Caroline Sweetheart Purple’. Unlike ‘Sweet Caroline Bewitched Imp’,     which does not produce flowers, even under short-day conditions,     ‘NCORNSP-023BWAM’ will flower sporadically throughout the season.

TABLE 2 Comparison of ‘NCORNSP-023BWAM’ with other Ipomoea batatas cultivars. ‘NCORNSP- ‘Sweet Caroline Sweetheart ‘Sweet Caroline Characteristic 023BWAM’ Purple’ Bewitched Imp’ Plant Habit Compact, Non- Moderately Compact Compact, Non- Twining, Upright to Compact, Non- Twining, Upright Twining, Upright Average Leaf Length: 12.7 cm Length: 9.9 cm Length: 12.1 cm Length and Width Width: 15.0 cm Width: 6.9 cm Width: 13.6 cm Foliage Color Yellow green (RHS Greyed purple brown Dark greyed purple 144A) with purple (RHS N200A, (RHS N186B) with (RHS N77A-N77B) N186A-N186B) with dark greyed purple at petiole junction brown yellow green (RHS 187A) and along midrib (RHS N200A, venation 146B-146C) tips Leaf Shape Tooth-slighly lobed. Entire. Deltoid with Slightly lobed to toothed. Deltiod base deltoid base Cordate with reniform-cordate base 

We claim:
 1. A new and distinct cultivar of Ipomoea batatas plant named ‘NCORNSP-023BWAM’, substantially as illustrated and described herein. 